Between Theory and Practice

Environmentalists consider invasions by exotic species of plants and animals to be one of the most serious environmental problems we face today, as well as one of the leading causes of biodiversity loss. We argue that in order to develop and enact sensible policies, it is crucial to consider two philosophical questions: (1) What exactly makes a species native or exotic, and (2) What values are at stake? We focus on the first of these two questions, and offer some preliminary suggestions with regard to the second. Through a series of case studies, we show that it is not always clear whether a species is native or exotic. We identify five possible criteria that could be used for distinguishing natives from exotics. Rather than identifying one of these criteria as the 'correct' one, we suggest that the concepts of 'native' and 'exotic' function more like what some philosophers have called cluster concepts. That is, there are several characteristics that are typical of native species, and a corresponding set of characteristics that are typical of exotic species. None of these characteristics is either necessary or sufficient for identifying a species as either native or exotic. We then identify several of the values that are at stake in dealing with exotic species, and we suggest that policies need to avoid being overly simplistic.

Section: Saysmentioning

confidence: 99%

“…Thus, invasives are a subcategory of non-natives. Donald Scherer (1994) has a similar classification scheme, though he uses the terms differently. Scherer uses 'non-indigenous' to refer to species existing outside of their historical ranges.…”

Section: The Degradation Criterionmentioning

confidence: 99%

Strangers in a Strange Land: The Problem of Exotic Species

Woods¹,

Moriarty²

2001

Strangers in a Strange Land: The Problem of Exotic Species

Woods

Moriarty

2001

Environmentalists consider invasions by exotic species of plants and animals to be one of the most serious environmental problems we face today, as well as one of the leading causes of biodiversity loss. We argue that in order to develop and enact sensible policies, it is crucial to consider two philosophical questions: (1) What exactly makes a species native or exotic, and (2) What values are at stake? We focus on the first of these two questions, and offer some preliminary suggestions with regard to the second. Through a series of case studies, we show that it is not always clear whether a species is native or exotic. We identify five possible criteria that could be used for distinguishing natives from exotics. Rather than identifying one of these criteria as the ‘correct’ one, we suggest that the concepts of ‘native’ and ‘exotic’ function more like what some philosophers have called cluster concepts. That is, there are several characteristics that are typical of native species, and a corresponding set of characteristics that are typical of exotic species. None of these characteristics is either necessary or sufficient for identifying a species as either native or exotic. We then identify several of the values that are at stake in dealing with exotic species, and we suggest that policies need to avoid being overly simplistic.

Exotic Species, Naturalisation, and Biological Nativism

Hettinger¹

2001

Contrary to frequent characterisations, exotic species should not be identified as damaging species, species introduced by humans, or species originating from some other geographical location. Exotics are best characterised ecologically as species that are foreign to an ecological assemblage in the sense that they have not significantly adapted with the biota constituting that assemblage or to the local abiotic conditions. Exotic species become natives when they have ecologically naturalised and when human influence over their presence in an assemblage (if any) has washed away. Although the damaging nature and anthropogenic origin of many exotic species provide good reasons for a negative evaluation of such exotics, even naturally-dispersing, nondamaging exotics warrant opposition. Biological nativists' antagonism toward exotics need not be xenophobic and can be justified as a way of preserving the diversity of ecological assemblages from the homogenising forces of globalisation. Implications for Yellowstone National Park policy are explored. KEYWORDS Exotics, native, nativism, naturalisation, Yellowstone National Park 'Invasive alien species … homogenise the diversity of creation. … Weedsslowly, silently, almost invisibly, but steadily-spread all around us until, literally encircled, we can no longer turn our backs. The invasion is now our problem, our battle, our enemy. … [We must] act now and act as one [in order to] beat this silent enemy.' Former U.S. Interior Secretary Bruce Babbitt (1998) 'I just hate them. They are genetically deviant miscreants that have no rightful place on this planet. We all have to be a part of this war on weeds.' Former Montana Governor Marc Racicot (Associated Press 1999) 'It's hard to imagine a New England roadside without its tawny day lilies and Queen Anne's lace, yet both these species are aliens marked for elimination. … Could it be these plants have actually improved the New England landscape, adding to its diversity and beauty? Shouldn't there be a statute of limitations on their alien status?' Harper's editor Michael Pollan (1994)